Crystal Structures and Phase Transitions of 3-Chloro-2,2-bis(chloromethyl)propionic Acid-1 and 1,3-Dichloro-2,2-dimethylpropane

The crystal structure of 3-chloro-2,2-bis(chloromethyl)propionic acid-1 was determined from single crystal data. The compound crystallizes in the acentric monoclinic space group P21. Lattice constants at T = 304 K are a = 6.961(1) Å, b = 9.979(2) Å, c = 12.0569(3) Å, b = 94.01(2)°. Structure refinement on 1736 independent reflections yielded R = 0.041. Two molecules are interconnected by hydrogen bridges to form dimers. Thermal analysis and temperature dependent X-ray and IR-measurements gave no indication of a phase transition in the range 150 K < T < 384 K. An order-disorder phase transition was detected for 1,3-dichloro-2,2-dimethylpropane at TI&#x2192;II = 194.3 K, with a plastic cubic phase in the range 194.3 K < T < 259.1 K. The lattice constant in space group Fm3m is a = 9.24 Å at 220 K with a thermal expansion coefficient a(200 K) = 2.6769 x 10–4 K–1. The entropy at the melting point Tm = 259.1 K and at the solid-solid phase transition TI&#x2192;II = 194.3 K is rather low giving strong evidence of a plastic phase. Powder X-ray diffraction pattern in the ordered phase at T = 160 K gave indication of monoclinic symmetry with a = 12.27 Å, b = 10.86 Å, c = 10.68 Å, b = 111.8°. Temperature dependent infrared measurements revealed the conformation of the molecule

Poly[ethano­lbis(μ3-2-thio­xo-1,2-dihydro­pyridin-1-olato)dilithium(I)]

The title compound, [Li2(C5H4NOS)2(C2H6O)]n, having two formula units in the asymmetric unit, forms infinite chains of Li2O2 rhombi along b, consisting of four independent Li and O atoms. Metal binding to 2-thio­oxo-1,2-dihydro­pyridin-1-olate occurs in a bidentate fashion via O and S, and in a monodentate manner via the N-oxide O atom. π–π Inter­actions between polymeric chains are evident from centroid-to-centroid distances of pyridine­thione fragments of 3.461 (6)–3.607 (6) Å. The N—O and C—S bond lengths are distinctively different from those in hitherto investigated NiII, ZnII and (H3C)2TlIII complexes of 2-thio­oxo-1,2-dihydro­pyridin-1-olate, but correlate with those reported for 1-hydr­oxy- and 1-alkoxy­pyridine-2(1H)-thio­nes in the solid state

Poly[aqua­[μ-4-(4-chloro­phen­yl)-2-thioxo-2,3-dihydro­thia­zol-3-olato]­sodium(I)]

The packing of the title compound, [Na(C9H5ClNOS2)(H2O)]n, in the crystal structure occurs by pairwise attachment of +sc- and −sc-arranged 4-(4-chloro­phen­yl)-2-thioxo-2,3-dihydro­thia­zol-3-olate subunits via S to sodium. Water mol­ecules that are bound in the axial position of the distorted octa­hedral coordination octahedron give rise to a stereogenic center at sodium

Crystal Structures and Phase Transitions of 3-Chloro-2,2-bis(chloromethyl)propionic Acid-1 and 1,3-Dichloro-2,2-dimethylpropane

The crystal structure of 3-chloro-2,2-bis(chloromethyl)propionic acid-1 was determined from single crystal data. The compound crystallizes in the acentric monoclinic space group P21. Lattice constants at T = 304 K are a = 6.961(1) Å, b = 9.979(2) Å, c = 12.0569(3) Å, b = 94.01(2)°. Structure refinement on 1736 independent reflections yielded R = 0.041. Two molecules are interconnected by hydrogen bridges to form dimers. Thermal analysis and temperature dependent X-ray and IR-measurements gave no indication of a phase transition in the range 150 K < T < 384 K. An order-disorder phase transition was detected for 1,3-dichloro-2,2-dimethylpropane at TI&#x2192;II = 194.3 K, with a plastic cubic phase in the range 194.3 K < T < 259.1 K. The lattice constant in space group Fm3m is a = 9.24 Å at 220 K with a thermal expansion coefficient a(200 K) = 2.6769 x 10–4 K–1. The entropy at the melting point Tm = 259.1 K and at the solid-solid phase transition TI&#x2192;II = 194.3 K is rather low giving strong evidence of a plastic phase. Powder X-ray diffraction pattern in the ordered phase at T = 160 K gave indication of monoclinic symmetry with a = 12.27 Å, b = 10.86 Å, c = 10.68 Å, b = 111.8°. Temperature dependent infrared measurements revealed the conformation of the molecule

2,2-Dichloro-N-(3,4-dimethyl­phen­yl)acetamide

In the title compound, C10H11Cl2NO, the N—H bond is syn to the 3-methyl substituent in the aromatic ring, similar to that observed in N-(3,4-dimethyl­phen­yl)acetamide and to the 3-chloro substituent in 2,2-dichloro-N-(3,4-dichloro­phen­yl)acetamide, and contrasting with the anti conformation observed for the 3-methyl substituent in 2,2,2-trichloro-N-(3,4-dimethyl­phen­yl)acetamide. On the other hand, it is anti to the C=O bond. An inter­molecular N—H⋯O hydrogen bond links mol­ecules into infinite chains along the b axis

2,2-Dichloro-N-(3,5-dimethyl­phen­yl)­acetamide

The structure of the title compound, C10H11Cl2NO, resembles those of 2,2-dichloro-N-phenyl­acetamide, 2,2-dichloro-N-(2-methyl­phen­yl)acetamide, 2,2-dichloro-N-(3-methyl­phen­yl)­acetamide, 2,2-dichloro-N-(4-methyl­phen­yl)acetamide, N-(3,5-dimethyl­phen­yl)acetamide and other acetanilides, with similar bond parameters. The mol­ecules in the title compound are linked into infinite chains through N—H⋯O and C—H⋯O hydrogen bonding

2,2-Dichloro-N-(2,3-dimethyl­phen­yl)acetamide

The conformation of the N—H bond in the title compound, C10H11Cl2NO, is syn to both the 2- and 3-methyl substituents in the aromatic ring, similar to that of the 2-chloro and 3-chloro substituents in 2,2-dichloro-N-(2,3-dichloro­phen­yl)acetamide and the 2-methyl substituent in 2,2-dichloro-N-(2-methyl­phen­yl)acetamide, but in contrast to the anti conformation observed with respect to the 3-methyl substituent in 2,2-dichloro-N-(3-methyl­phen­yl)acetamide. The bond parameters in the title compound are similar to those in 2,2-dichloro-N-phenyl­acetamide and other acetanilides. The mol­ecules of the title compound are linked into chains through N—H⋯O and C—H⋯O hydrogen bonding

2-Chloro-N-(3-methyl­phen­yl)acetamide

The conformation of the N—H bond in the structure of the title compound, C9H10ClNO, is syn to the meta-methyl group, in contrast to the anti conformation observed with respect to the meta-nitro group in 2-chloro-N-(3-nitro­phen­yl)­acetamide. The asymmetric unit of the title compound contains two mol­ecules. The geometric parameters of the title compound are similar to those of 2-chloro-N-(4-methyl­phen­yl)­acetamide, 2-chloro-N-(3-nitro­phen­yl)acetamide and other acetanilides. Dual inter­molecular N—H⋯O hydrogen bonds link the mol­ecules in the direction of the a axis

Poly[diaqua(μ2-3-carboxypyrazine-2-carboxylato)(μ2-pyrazine-2,3-dicarboxylic acid)potassium(I)]

The structural unit of the title compound, [K(C6H3N2O4)(C6H4N2O4)(H2O)2]n, consists of one potassium cation, one hydrogen pyrazine-2,3-dicarboxyl­ate anion, one pyrazine-2,3-dicarboxylic acid mol­ecule and two water mol­ecules; this is twice the asymmetric unit, since the potassium cation lies on an inversion centre. Each anion or acid mol­ecule is linked to two potassium cations, while the potassium cation has contacts to four symmetry-equivalent organic ligands, with two different coordination modes towards this cation. In addition, each potassium cation is coordinated by two water O atoms, raising the coordination number to eight. One of the carboxyl groups of the acid retains its H atom, which forms a hydrogen bond to a coordinated water mol­ecule. The other carboxyl group is deprotonated in half of the ligands and protonated in the other half, taking part in a strong O—H⋯O hydrogen bond disordered over an inversion centre. The stabilization of the crystal structure is further assisted by O—H⋯O and O—H⋯N hydrogen bonds in which water acts as the donor